Germanicus had, by virtue of a decree of the Senate, supreme powers in the East; as a result his opinion carried the day, notwithstanding all the efforts that Piso made to prevent his sacrificing Vonones, whom Piso by way of compensation entertained, treated with honour, and openly took under his protection. Towards the middle of the year 18, Germanicus crowned Zenon King of the Armenians in Artaxata, a son of Polemon, King of Pontus. When, however, Germanicus asked Piso to send into Armenia a section of the legions placed under his command, to make an armed demonstration in favour of the new sovereign, Piso refused. Theoretically and by virtue of the decrees of the Senate, Germanicus had the right to give orders to Piso, and Piso ought to have obeyed them. On the other hand, Piso represented Tiberius; and with Germanicus, as with every other human authority, it was not enough to possess the power, there was needed also the hardihood to use it. In the face of Piso’s energy and the authority of Tiberius, who stood behind Piso, Germanicus did not dare to insist. It is easy, however, to picture the fury and rage of Germanicus’s friends and flatterers, to whom this kind of surveillance to which Germanicus was subjected became more intolerable, the more it limited indirectly their own authority. In their fury, they determined to have their revenge, and they were not long in finding an opportunity, though it cost them dear. Artabanus, the King of the Parthians, encouraged by the pliability of Germanicus, sent to ask him to forbid Vonones to live in Syria, on the ground that, as that province bordered on his Empire, Vonones could easily use it as a base from which to intrigue against him. In view of the fact that Vonones was in Syria as the guest of Piso, the Parthian King was asking Germanicus in so many words to forbid Piso to protect him. The demand was, in truth, excessive and somewhat humiliating for Rome; but Germanicus’s _entourage_ saw in this demand a means of humiliating Piso, and worked and talked to such effect that Germanicus conceded to it and shut Vonones up in a city in Cilicia. A checkmate had been inflicted on Piso, but the price of it was a humiliation for Rome. Piso and his party had good reason for accusing Germanicus and his _entourage_ of compromising with singular levity the prestige of Rome in the East.